Commanding the detached force in the Tietar Valley was General Robert Wilson. Wilson was one of the more colourful generals to be active in the Peninsula. He was born in 1777 as the son of the artist Benjamin Wilson. When his father died in 1789 young Wilson joined the 15th Light Dragoons and displayed both courage and skill at the Battle of Villers en Cauchies five years later. His continued exemplary service saw him knighted in 1801, but he then put everything at risk by eloping with the teenage daughter of a senior army officer.
Perhaps to stay out of the way of his irate in-laws, Wilson and his new wife went to Russia to work at the British Embassy, but in 1807 he was expelled as a spy. Within months Britain received an appeal for help against the French from the Portuguese. Among the things the Portuguese wanted was British officers to retrain the Portuguese Army. Wilson volunteered and in the summer of 1808 went to Lisbon to help organise the Loyal Lusitanian Legion.
In 1809 he marched into Spain with the Legion alongside the British army under Sir John Moore. But when Moore began his retreat to Corunna, Wilson disobeyed a direct order to do likewise and instead retreated back to Portugal by way of Almeira, which he garrisoned and equipped to withstand a French siege before falling back into Portugal. When General Lapisse launched the inevitable siege of Almeida, Wilson attacked with such energy and determination that Lapisse estimated his force to be three times the size it really was. Lapisse fell back into Spain. Thus when Wellesley came to Lisbon to relaunch British involvement in the Peninsular War much more of Portugal was free of the French than would have been the case without Wilson.
Wilson thereafter co-operated closely with Wellesley, his fine work with the Portuguese force in the Tietar Valley during the Talavera campaign being typical of how well the two men worked together. In 1812, with Russia now at war with France, Wilson was sent by the British government back to Russia. There he advised the Russian generals on his experiences of leading light troops against the French in the Peninsula.
When peace came in 1815, Wilson returned to Britain and went into politics as a radical. He served as an MP from 1818 to 1831. On one occasion he was attending a radical demonstration when the local magistrate called out the army. The situation was becoming ugly with some protestors throwing stones, and the soldiers loading their muskets. Wilson pushed his way to the fore and boldly marched into open space between demonstrators and soldiers. The officer commanding the soldiers recognised Wilson and ordered his men to retire, while the demonstrators heeded Wilson's plea to go home quietly. Wilson eventually rose to be a full general and was Governor of Gibraltar in the 1840s. He died in 1849 leaving a distraught widow and 13 children.